Fuel injection nozzle assembly



E. BLUHM FUEL INJECTION NOZZLE ASSEMBLY Filed June 15, 1967 0 M w w m kn k k v T N w .Vma. W 1 an .MWW$& w

E/zzzer 5/11/2122 A TTORNE Y r f /Z f l f f VKKf/ffl Ill/f Aug. 12, 1969United States Patent 3,460,760 FUEL INJECTION NOZZLE ASSEMBLY ElmerBluhm, Grandville, Micl1., assignor to General Motors Corporation,Detroit, Mich, a corporation of Delaware Filed June 15, 1967, Ser. No.646,258 Int. Cl. Bb 15/00, N30

US. Cl. 239-1323 4 Claims ABSTRACT OF THE DISCLOSURE A cooled fuelinjection nozzle assembly provides a holder and abutting nozzle, thelatter having a central needle valve and fuel receiving chamber.Oppositely disposed duel delivery ducts in the nozzle supply fuel toopposite sides of said chamber and connect through a semiarcuate ductbetween the nozzle and holder with a single supply duct in the holder.Coolant passages in the nozzle are connected with inlet and outlet ductspassing through hollow dowels in the holder and nozzle. The dowels areangularly spaced from the delivery ducts and index the nozzle and holderto properly locate their connecting ducts.

The invention herein described was made in the course of work under acontract or subcontract thereunder with the Department of Defense. Thisinvention relates to fuel injection nozzles for internal combustionengines and more particularly to a cooled fuel injection nozzle assemblyof compact size and improved construction.

In the design of cooled fuel injection nozzles of the present type, itis necesary to provide several fluid conducting passages between thespray nozzle and its holder to provide for delivery of fuel to thedelivery valve as well as for the supply to and discharge of coolingfuel from the nozzle tip. In order to provide a compact nozzle assembly,these passages may extend through the annular abutting surfaces of thenozzle and holder which surround the centrally located needle valve andits associted components. A locating dowel is generally used to properlylocate the holder and nozzle passages. This arrangement requires severalconnecting holes in the abutting ends of the holder and nozzle and hasled to the use in some nozzles of a single high-pressure fuel supplyduct in the nozzle for supplying fuel to the fuel receiving chambersurrounding the needle valve. Such an arrangement has been found toresult in excessive rates of fuel flow into the chamber leading toerosion within the nozzle as well as flow limitation due to unbalancedflow into the chamber.

The present invention provides a compact cooled injection nozzleassembly in which dual delivery ducts are utilized in the nozzle so asto supply fuel in a balanced manner to opposite sides of the fuelreceiving chamber. The duel ducts are connected by a semiannular ductformed between the holder and nozzle and which is supplied by a singlelarger duct in the holder. Coolant inlet and outlet passages extendthrough the abutting surfaces of the holder and nozzle at pointsangularly spaced from each other and from the semiannular duct and thesepass through a pair of hollow dowels which extend between the holder andnozzle and properly index them to correctly locate the variousconnecting passages. This construction, by combining the coolantpassages and locating dowel openings, reduces the number of holes neededin the nozzle end and provides a compact nozzle assembly havingdesirable fuel distribution and coolant flow characteristics as well asother advantages which will be apparent from the following descriptionof a preferred embodiment in which:

FIGURE 1 is a longitudinal cross-sectional view of a fuel injectionnozzle assembly arranged according to the invention, the view beingtaken generally in the plane indicated by the line 11 of FIGURE 2;

FIGURE 2 is a lateral cross-sectional view taken generally in the planeindicated by the line 22 of FIG- URE 1 at the location of certain nozzlefuel connections;

FIGURE 3 is a fragmentary longitudinal cross-sectional view takengenerally in the planes indicated by the line 3-3 of FIGURE 2 andshowing portions of the inlet and outlet coolant ducts.

FIGURE 4 is a lateral cross-sectional view taken generally in the planeindicated by the line 4-4 of FIG- URE 1 and showing the nozzle abuttingsurface of the holder;

FIGURE 5 is a lateral cross-sectional view taken generally in the planeindicated by the line 5-5 of FIG- URE 1 and showing the holder abuttingsurface of the nozzle;

FIGURE 6 is a fragmentary longitudinal cross-sectional view takengenerally in the plane indicated by the line 6-6 of FIGURE 5 and showingportions of the fuel delivery ducts and coolant passages; and

FIGURE 7 is a transverse cross-sectional view taken generally in theplane indicated by the line: 7-7 of FIG- URE l and showing portions ofthe coolant passages.

Referring more specifically to the drawings numeral 10 generallyindicates a fuel injection nozzle assembly arranged according to theinvention. Nozzle assembly 10 includes a nozzle holder 12 having a lowerend 14 which abuts the upper end 16 of an injection or spray nozzle 18which is secured against the holder by a cap nut 20.

Holder 12 includes a central bore 22 which extends through a smalleropening 24 to lower end 14. Bore 22 connects at its upper end with anenlarged compartment 26 which connects with an internally threadedconnection 28. Coil spring means 30 are seated in compartment 26 andurge downwardly a rod 34 disposed in bore 22. Chamber 26 is alsoconnected with the lower end 14 of the holder by a drilled passage orduct 36 (FIGURES 24) for a purpose to be subsequently described. Asecond internally threaded connector 38 extends from one side of holder12 and connects through drilled passages or ducts 40 and 42 with thelower end 14. Opposite connector 38 is an externally threaded highpressure connector 44 which connects through passages or ducts 46 and 48with the lower end 14.

Spray nozzle 18 includes a central bore: 50 having an upper diameter 52larger than its lower diameter 54 and terminating in a tapered seat 56adjacent an orificed spray tip 58. An enlarged fuel receiving chamber 60is formed intermediate the upper and lower bore diameters 52 and 54.Bore 50 receives a needle valve 62 which is closely fitted to the upperdiameter 52 of the bore for reciprocation therein along a longitudinalaxis 63. The needle valve includes a reduced lower portion 64 whichextends with substantial clearance through the lower bore diameter 54seating against seat 56 to normally prevent flow from chamber 60 throughspray tip 58. The upper end of needle valve 62 extends through opening24 into engagement with rod 34 such that the bias of spring 30 normallyholds valve 62 against the seat 56.

On its upper end 16, the nozzle has a semiarcuate groove 65 which iscentered on the axis 63 and cooperates with the lower end 14 of theholder to form a semiannular duct 66 which connects intermediate itsends with duct 48 of the holder. A pair of fuel delivery ducts 70 extendin the nozzle from opposite ends of duct 66 to opposite edges of chamber60 for the delivery of fuel to the opposite sides of the chamber.

Coolant passages are formed in part by a pair of hollow dowels 72 whichare received in counterbored portions of ducts 42 and 36 of the holder12 as well as mating counterbored portions of the nozzle 18. Thepassages extend through dowels 72, one of which connects duct 42 with aninlet duct 74 in the nozzle while the other connects duct 42 with aninlet duct 74 in the nozzle while the other connects duct 36 with anozzle outlet duct 76. The lower end of nozzle 18 is of reduced diameterand includes a flanged sleeve 78 which is brazed at its lower and upperextremities to the nozzle body 79. The sleeve cooperates with the nozzlebody 79 to enclose interconnecting coolant passages connecting withinlet and outlet ducts 74, 76 and formed by an annular groove 80 locatedadjacent the spray tip, a pair of opposed flats 82 extending alongopposite sides of body 79 and a pair of segmental recesses 84.

In operation, high-pressure fuel is supplied through connector 44 andducts 46, 48 to semiannular duct 66 thence through ducts 70 to chamber60. Pressure in chamber 60 acts upon needle valve 62 opening the valveat a predetermined pressure to permit the flow of fuel from chamber 60through lower bore diameter 54 and out spray tip 58 in a conventionalmanner. Fuel leakage through the upper bore diameter 52 passes throughopening 24 and bore 22 to chamber 26 and out through con nector 28.

Cooling of the nozzle tip is accomplished by low pressure cooling fuelsupplied to the nozzle through connector 38 and ducts 40 and 42 andpassing through the hollow center of one of the dowels 72 and throughthe connecting duct 74 to the nozzle coolant passage formed by one ofthe segmental recesses 84. From the recess 84 the cooling fuel isdirected along one of the flats 82 to annular groove 86) which conductsthe fuel in either direction around the end portion of the nozzlecooling it. The cooling fuel then is directed out through the second ofthe flats 82 and the second of the recesses 84 to outlet passage 76,through the second of the dowels 72 and through duct 36 to chamber 26 inthe holder from whence it passes out through connector 28.

While the various features of the present invention have beenillustrated by reference to a preferred embodiment, it should beapparent that certain changes might be made without departing from thespirit and scope of the inventive concepts disclosed.

I claim:

1. A fuel injection nozzle assembly for an internal combustion engine,said assembly including a nozzle holder having a plurality of fuelconnections,

a spray nozzle sealingly abutting one end of said holder and having aspray tip spaced from said holder,

an enlarged fuel receiving chamber in said nozzle intermediate saidspray tip and said holder,

fuel delivery means extending longitudinally through said chamber andconnecting said chamber and spray tip, said means being responsive atleast in part to fuel pressure in said chamber to control fuel flow fromsaid chamber to said spray tip, said delivery means having alongitudinal axis,

coolant passages in said nozzle and at least partially surrounding saidfuel delivery means intermediate said chamber and said spray tip,

a plurality of fluid conducting passages extending through the abuttingportions of said nozzle and holder and connecting said nozzle chamberand coolant passages respectively with said holder fuel connections, andthe improvement comprising at least one hollow dowel extending into andindexing said holder and nozzle through their abutting portions toproperly locate the connecting portions of said fluid conductingpassages, one of said passages extending through the hollow center ofsaid dowel whereby said dowel defines a portion of said one passage,

said fluid conducting passages including high pressure fuel ductsconnecting one of said fuel connections with said nozzle chamber andsaid high pressure fuel ducts including a delivery duct in said holderspaced from said axis,

a semiannular duct defined by said holder and said nozzle, saidsemiannular duct being centered on said axis and terminating on oppositesides thereof, said delivery duct connecting with the semiannular ductintermediate its ends, and

a pair of delivery ducts in said nozzle disposed on opposite sides ofsaid fuel delivery means and connecting said fuel receiving chamber withopposite ends of said semi-annular duct,

said hollow dowel being angularly spaced from said high pressure ductsand defining a passage other than. one of said high pressure ducts.

2. A fuel injection nozzle assembly for an internal combustion engine,said assembly including a nozzle holder having a plurality of fuelconnections,

a spray nozzle sealingly abutting one end of said holder and having aspray tip spaced from said holder,

an enlarged fuel receiving chamber in said nozzle intermediate saidspray tip and said holder,

fuel delivery means extending longitudinally through said chamber andconnecting said chamber and spray tip, said means being responsive atleast in part to fuel pressure in said chamber to control fuel flow fromsaid chamber to said spray tip, said delivery means having alongitudinal axis,

coolant passages in said nozzle and at least partially surrounding saidfuel delivery means intermediate said chamber and said spray tip,

a plurality of fluid conducting passages extending through the abuttingportions of said nozzle and holder and connecting said nozzle chamberand coolant passages respectively with said holder fuel connections, andthe improvement comprising at least one hollow dowel extending into andindexing said holder and nozzle through their abutting portions toproperly locate the connecting portions of said fluid conductingpassages, one of said passages extending through the hollow center ofsaid dowel whereby said dowel defines a portion of said one passage,

said fluid conducting passages including high pressure fuel ductsoccupying adjacent the abutting surfaces of said holder and nozzleapproximately half the angular distance surrounding said axis andcoolant distribution ducts including inlet and outlet ducts connectingcertain of said fuel connections with said nozzle coolant passages, saidinlet and outlet ducts passing through the abutting surfaces of saidholder and nozzle at points angularly spaced from one another and fromsaid high pressure fuel ducts, said hollow dowel forming a part of anddefining one of said inlet and outlet ducts.

3. The assembly of claim 2 and further comprising a second hollow dowelextending into and indexing said holder and nozzle, said second dowelforming a part of and defining the other of said inlet and outlet ducts.

4. A fuel injection nozzle assembly for an internal combustion engine,said assembly including a nozzle holder having a plurality of fuelconnections,

a spray nozzle sealingly abutting one end of said holder and having aspray tip spaced from said holder,

an enlarged fuel receiving chamber in said nozzle intermediate saidspray tip and said holder,

fuel delivery means extending longitudinally through said chamber andconnecting said chamber and spray tip, said means being responsive atleast in part to fuel pressure in said chamber to control fuel flow fromsaid chamber to said spray tip, said delivery means having alongitudinal axis,

coolant passages in said nozzle and at least partially surounding saidfuel delivery means intermediate said chamber and said spray tip,

a plurality of fluid conducting passages extending ducts passing throughthe abutting surfaces of said holder and nozzle at points angularlyspaced from one another and from said high pressure fuel ducts and apair of hollow dowels extending between and indexing said holder andnozzle to properly locate their connecting ducts, said inlet and outletducts each extending through the hollow center of one of said dowels,whereby said dowels each define a portion high pressure fuel ductsconnecting one of said fuel con- 10 f one f i i l and Outlat m nectionswith said nozzle chamber and including a delivery duct in said holderspaced from said axis, a semicircular duct defined by said holder andsaid nozzle, said semiannular duct being centered on said ReferencesCited UNITED STATES PATENTS axis and terminating on opposite sidesthereof, said 15 1,879,985 9/1932 Lummen 239 533 delivery ductconnecting with the semiannular duct 2,108,547 2/1933 Broeze 239 533intermediate its ends, and a pair of delivery ducts in 2 8 014 5 1959Konrad et 1 239 132 5 said nozzle disposed on opposite sides of saidfuel delivery means and connecting said fuel receiving FOREIGN PATENTSchamber with opposite ends of said semiannular duct, 20 441 181 1/1936Great Britain coolant distribution ducts including inlet and outletducts connecting others of said fuel connections with said nozzlecoolant passages, siad inlet and outlet EVERETT KIRBY Primary Examlmr

